You will definitely not be able to enjoy the fresh air, silence and solitude in the city, but do not forget about the principles of eco-tourism on such trips. The environment should be protected: do not litter, use reusable dishes, be careful with the sights. If you want to make your vacation more conscious, walk more. Yes, in some cities it is difficult, but if you develop a route in advance and book hostels or hotels according to this route, you can minimize the use of transport.
Meet local customs. As strange as it may sound, many cities have so-called "urban legends" and customs. I really advise you to refrain from such traditions as "happy handshake", when, by touching some part of the statue, you can make a wish or just become happier. Remember about respect, such strokes very often harm monuments. But you can get a little bit of the local community, for example, by jogging in Central Park in New York or joining the general siesta in the cities of hot countries.